Feb. 19 morning update: Bertha approaching the pit

Posted on Feb 19 2015 10:19 AM

Since yesterday afternoon's update, Seattle Tunnel Partners has built two new concrete tunnel rings and continued mining into the southern wall of the SR 99 tunnel access pit. Bertha has travelled 14 feet since mining resumed late Tuesday evening, and work is proceeding as planned.

Here's video footage (links to YouTube) of Wednesday's work. Crews from STP and manufacturer Hitachi Zosen are continuing to use caution to protect the machine from overheating or further damage as they mine through 20 feet of unreinforced concrete to reach the interior of the pit.